1. Classification of Matter Matter Stuff of which all materials are made: anything that has mass and takes up space.

2. Define Atoms- Extremely small building blocks of matter  All matter is composed of (made of) atoms  Atoms CANNOT be broken down into smaller pieces by chemical means  The smallest distinct units in a sample of matter Elements are made up the same atoms!  Elements cannot be decomposed (broken down) into other substances.

3. Pure Substances  Element  composed of identical atoms  EX: copper wire, aluminum foil

4. Pure Substances  Element Another example:  This vase is also made of copper.

5. Define  Molecule – a combination of 2 or more atoms (same or different) that are covalently bonded.  A molecule is the smallest particle of a substance which exhibits the physical and chemical characteristics of the substance.  Diatomic molecules of elements : H 2 O 2 Cl 2 N 2 F 2 Br 2 I 2 What does the prefix Di mean?

6. Define Examples of compounds: H 2 O CO 2 CaSO 4 HBR Na 2 OKOH H 2 CO 3 Compounds A compound is made of 2 or more different elements bonded together in a fixed proportion.

7. Pure Substances  Compound  composed of 2 or more elements in a fixed ratio  properties differ from those of individual elements  EX: table salt (NaCl)

8. Pure Substances  For example… Two different compounds, each has a definite composition.

9. Compounds Slight differences in combinations of atoms can have large difference in properties! Same elements but completely different substances! H 2 O- water, H 2 O 2 – hydrogen peroxide C 2 H 6 O – ethanol, drinkable C 2 H 6 O 2 – ethylene glycol, poisonous

10. Pure Substances Compounds Can be decomposed into simpler substances by chemical changes, always in a definite ration Elements cannot be decomposed into simpler substances by chemical changes Same kind of particles throughout

11. Mixtures  Variable combination of 2 or more pure substances.  Homogeneous Mixture (Solution) even distribution of components very small particles particles never settle EX: saline solution

12. Mixture  Mixtures are two or more substance that are not chemically combined.  Mixtures do not have a fixed composition  Mixtures do not have constant boiling points or melting points  Variable composition  Components retain their characteristic properties

13. Mixture  May be separated into pure substances by physical methods  Mixtures of different compositions may have widely different properties.

14.  Pure Substances and Mixtures

15. Which is it? Element Compound Mixture

16. Mixtures can be separated! How?  By eye  Filtration to separate solid and liquid  Distillation to separate two or more liquids with different boiling points  Chromatography to separate pure liquids or solutions of compounds

17. Mixtures  Variable combination of 2 or more pure substances. HeterogeneousHomogeneous

20. Types of mixtures  Homogeneous mixture -1 phasephase -uniform properties in a sample -same composition in a sample eg:sugar and water Heterogeneous mixture -2 or more phases (with same or different physical states) -each phase has different properties eg: oil and water, sand and water

21. A. Matter Flowchart MATTER Can it be physically separated? Homogeneous Mixture (solution) Heterogeneous MixtureCompoundElement MIXTUREPURE SUBSTANCE yesno Can it be chemically decomposed? noyes Is the composition uniform? noyes ColloidsSuspensions

22. Mixtures  Heterogeneous Mixture  uneven distribution of components  colloids and suspensions  EX: granite

23. Mixtures  Solution  homogeneous  very small particles  no Tyndall effect Tyndall Effect  particles don’t settle  EX: rubbing alcohol

24. Mixtures  Colloid  heterogeneous  medium-sized particles  Tyndall effect  particles don’t settle  EX: milk

25. C. Mixtures  Suspension  heterogeneous  large particles  Tyndall effect  particles settle  EX:fresh-squeezed lemonade

26. Mixtures  Examples:  mayonnaise  muddy water  fog  saltwater  Italian salad dressing colloid suspension colloid solution suspension

27. Matter Flowchart  Examples:  graphite  pepper  sugar (sucrose)  paint  soda element hetero. mixture compound hetero. mixture solution

28. Classifying Matter

29. This ends your notes. The next 2 slides contain practice problems. Read them. You do not have to copy.

30. PRACTICE PROBLEMS #4 1. Classify the following as an element, compound, or mixture (heterogeneous or homogeneous).  _____ air_____ oxygen  _____ tin can_____ sugar  _____ Windex_____ crude oil  _____ suntan lotion_____ gummi bear 2. A white solid is dissolved in water. The resulting colorless, clear liquid is boiled in a beaker until dryness. White crystals remain in the beaker. The liquid can be classified as a(n) ______________. 3. Classify the following as physical or chemical changes.  _____ photosynthesis_____ baking  _____ writing with pencil _____ snowing HO E EC HE HO Homogeneous mixture CC PC CC PC

31. GROUP STUDY PROBLEM #4 1. Classify the following as an element, compound, or mixture (heterogeneous or homogeneous).  _____ wine_____ root beer  _____ penny_____ table salt  _____ Bleach_____ wood  _____ diamond_____ vinegar 2. A clear blue liquid in an open beaker was left in the hood. After 1 week, the beaker contained only blue crystals. The original liquid can be classified as a(n) ______________. 3. Classify the following as physical or chemical changes.  _____ perspiration_____ sugar dissolving  _____ fermentation_____ aging